They didn't know what I was talking about and said that the baggage handlers go through security as well,
Just because they
believe that the baggage handlers go through does not mean that they do. The engineers definitely do not as they start their day at the hangar and then end up airside at the terminal in either a car, a tug or in an aircraft under tow.
As a related point, I went through Heathrow, Bangkok and KL in the last few weeks. I made a point of checking in the airside cafes and restaurants...some very nice kitchen knives in them, in the
sterile area, not chained or housed, sitting on a bench.